Physical Sciences and Mathematics Commons^™

An Experimental And Computational Evaluation Of The Importance Of Molecular Diffusion In Gas Gravity Currents, Jeremy Jac Herman

Graduate Theses and Dissertations

The accidental release of hazardous, denser-than-air gases during their transport or manufacture is a vital area of study for process safety researchers. This project examines the importance of molecular diffusion on the developing concentration field of a gas gravity current released into a calm environment. Questions which arose from the unexpectedly severe explosion in 2005 at Buncefield, England were of particular interest. The accidental overfilling of a large tank with gasoline on a completely calm morning led to a massive open air explosion. Forensic evidence showed that at the time of ignition, a vapor cloud, most of which now appears …

Utilizing Persistent Scatterer Interferometry To Investigate The Nature And Factors Controlling Nile Delta Subsidence, El Hachemi Yousef Bouali

Masters Theses

The Nile Delta in Egypt is being threatened by two continuous and relatively slow hazards: encroachment from the Mediterranean Sea as sea levels rise and land subsidence of the delta itself. The magnitude of sea level rise has been actively monitored, while the subsidence of the Nile Delta has not been adequately quantified spatially and temporally. Instead, all previous studies have either focused on measuring average Holocene subsidence rates or modern subsidence rates on local scales (point- or city-scale).

The overall study objective is three-fold: (1) to measure and map the spatial variations in subsidence rates across the entire Nile …

Synthesis And Structures Of New Three-Dimensional Copper Metal-Organic Frameworks, Nitin Kumar Pally

Masters Theses & Specialist Projects

Metal-organic frameworks (MOFs) are crystalline materials with metal ions covalently bonded to organic ligands. The ligands act as spacers often creating a porous structure with very high pore volume and surface area. MOFs are known for their robust structures, high porosity, and different chemical functionalities and are considered for applications in adsorptions, separations, catalysis and gas storage. This work focuses on the synthesis of new MOFs using copper compounds. Different types of carboxylate ligands were used for the synthesis. Two new copper-organic frameworks, [Cu₃(pyz)(btc)] (1), and [(Cu₃(btc))•xH₂O] (2) (btc= benzene-1,3,5-tricarboxylate, pyz= pyrazine) have been …

Synthesis And Characterization Of Manganese Pyridazyl Complexes, Sana Shah

Masters Theses & Specialist Projects

Heterocyclic’s and their fused-ring derivatives have been of interest for their use in electronic materials due to their ease of production, synthetic versatility, and low cost compared to traditional inorganic materials like silicon. Pyridazines have been found to be useful in catalysis gas storage, polymeric sensors and biological mimetics. When a transition-metal is fused into a synthesized pyridazine, unique properties such as conductivity and optics are allowed. In this work, synthesized pyridazine complexes will be analyzed by mass spectroscopy, elemental analysis, nuclear magnetic resonance, imaging, x-ray crystallography, and infrared spectroscopy. We are interested in synthesizing organometallic pyridazines and manganese pyridazyl …

Interactive Wireless Sensor For Remote Trace Detection And Recognition Of Hazardous Gases, Audrey Lama

Masters Theses & Specialist Projects

The interactive wireless sensor detects many hazardous gases such as Hexane, Propane, Carbon monoxide and Hydrogen. These gases are highly toxic and used in different kinds of manufacturing industries, domestic purpose and so on. So, building a sensor that can detect this kind of gases can save the environment; prevent the potential for explosion, and endangering human life. In long term, interactive wireless sensor can also prevent the financial losses that might occur due to the hazardous incident that might occur due to these toxic gases.

Hexane is a colorless, strong gas which inhaled in significant amounts by a person …

Eastern Deciduous Forest Phenology And Vegetative Vigor Trends From 2000 To 2013, Mammoth Cave National Park, Ky, Sean Taylor Hutchison

Masters Theses & Specialist Projects

Global climate change is predicted to affect environmental systems at the midlatitudes, but the scope, severity, and outcomes of these impacts are yet to be fully understood. This study focuses on the implications of short-term climate variability for forests in central Kentucky. Using a Normalized Difference Vegetation Index (NDVI) calculated from MODerate-Resolution Imaging Spectroradiometer (MODIS) instrument data, the photosynthetic activity of vegetation at Mammoth Cave National Park (MACA) is tracked from 2000 to 2013. Three methods were employed to examine the changes and climate influences in vegetation over the study period: 1) aggregating the NDVI of the Park by year …

Global Digital Elevation Model Accuracy Assessment In The Himalaya, Nepal, Luke G. Miles

Masters Theses & Specialist Projects

Digital Elevation Models (DEMs) are digital representations of surface topography or terrain. Collection of DEM data can be done directly through surveying and taking ground control point (GCP) data in the field or indirectly with remote sensing using a variety of techniques. The accuracies of DEM data can be problematic, especially in rugged terrain or when differing data acquisition techniques are combined. For the present study, ground data were taken in various protected areas in the mountainous regions of Nepal. Elevation, slope, and aspect were measured at nearly 2000 locations. These ground data were imported into a Geographic Information System …

Molecular Level Interaction Of Human Fibroblast Growth Factor-1 (Hfgf-1) With Phloridzin, Rammohan Paripelly

Masters Theses & Specialist Projects

Fibroblast growth factors (FGFs) are a family of growth factors which includes twenty three proteins. FGFs work as modulators for various cellular activities like mitosis, differentiation and survival. Among the FGF family, human fibroblast growth factor-1 (hFGF-1), which is also known as acidic fibroblast growth factor, is a potent angiogenic agent, involved in the formation of new blood vessels in various tissues. hFGF-1 is regarded as a prototype of the FGF family. It serves as one of the potential targets in tumor inhibition and obesity due to its involvement in new blood vessel formation in cancerous regions and adipose tissues. …

An Integrated Multidisciplinary Nanoscience Concentration Certificate Program For Stem Education, Karen S. Martirosyan, Mikhail M. Bouniaev, Malik Rakhmanov, Ahmed Touhami, Nazmul Islam, Davood Askari, Tarek Trad, Dmitri Litvinov, Sergey E. Lyshevski

Physics and Astronomy Faculty Publications and Presentations

Integration of nanoscience and nanotechnology curricula into the College of Science, Mathematics, and Technology (CSMT) at the University of Texas at Brownsville (UTB) is reported. The rationale for the established multidisciplinary Nanoscience Concentration Certificate Program (NCCP) is to: (i) develop nanotechnology-relevant courses within a comprehensive Science, Engineering and Technology curriculum, and, to offer students an opportunity to graduate with a certificate in nanoscience and nanotechnology; (ii) to contribute to students' success in achieving student outcomes across all college's majors, and, improve the breath, depth and quality of science, technology, engineering and mathematics (STEM) graduates' education; (iii) through NCCP, recruit certificate- …

Detection Of Pulsar Beams Deflected By The Black Hole In Sgr A*: Effects Of Black Hole Spin, Sourabh Nampalliwar, Richard H. Price, Teviet Creighton, Fredrick A. Jenet

Physics and Astronomy Faculty Publications and Presentations

Some Galactic models predict a significant population of radio pulsars close to the Galactic center. Beams from these pulsars could be strongly deflected by the supermassive black hole (SMBH) believed to reside at the Galactic center and as a result reach Earth. Earlier work assuming a Schwarzschild SMBH gave marginal chances of observing this exotic phenomenon with current telescopes and good chances with future telescopes. Here we study whether those estimates are significantly affected by SMBH spin. We find that spin effects make a negligible difference in detectability, but the pattern of pulse arrival times is clearly affected. In particular, …

Detection Of Design Flaws In Object Oriented Software Systems, Sneha Lalit

Culminating Projects in Computer Science and Information Technology

As the object oriented systems evolve, the original design is distorted and bad smells or deviation from good design heuristics are observed in the source code. Presence of design flaws in the software distorts the original design pattern realization and affects maintainability and flexibility of the code. In this paper, we study software evolution, design flaw detection and correction strategies. We focus on two design flaws and demonstrate their detection and correction. To detect design flaws we refer multiple strategies, define our own strategies and apply those to sample java software. A set of metric values are measured for the …

Towards A Hybrid Framework For Detecting Input Manipulation Vulnerabilities, Sun Ding, Hee Beng Kuan Tan, Lwin Khin Shar, Bindu Madhavi Padmanabhuni

Research Collection School Of Computing and Information Systems

Input manipulation vulnerabilities such as SQL Injection, Cross-site scripting, Buffer Overflow vulnerabilities are highly prevalent and pose critical security risks. As a result, many methods have been proposed to apply static analysis, dynamic analysis or a combination of them, to detect such security vulnerabilities. Most of the existing methods classify vulnerabilities into safe and unsafe. They have both false-positive and false-negative cases. In general, security vulnerability can be classified into three cases: (1) provable safe, (2) provable unsafe, (3) unsure. In this paper, we propose a hybrid framework-Detecting Input Manipulation Vulnerabilities (DIMV), to verify the adequacy of security vulnerability defenses …

Adaptive Computer‐Generated Forces For Simulator‐Based Training, Expert Systems With Applications, Teck-Hou Teng, Ah-Hwee Tan, Loo-Nin Teow

Research Collection School Of Computing and Information Systems

Simulator-based training is in constant pursuit of increasing level of realism. The transition from doctrine-driven computer-generated forces (CGF) to adaptive CGF represents one such effort. The use of doctrine-driven CGF is fraught with challenges such as modeling of complex expert knowledge and adapting to the trainees’ progress in real time. Therefore, this paper reports on how the use of adaptive CGF can overcome these challenges. Using a self-organizing neural network to implement the adaptive CGF, air combat maneuvering strategies are learned incrementally and generalized in real time. The state space and action space are extracted from the same hierarchical doctrine …

A Local Social Network Approach For Research Management, Xiaoyan Liu, Zhiling Guo, Zhenjiang Lin, Jian Ma

Research Collection School Of Computing and Information Systems

Traditional methods to evaluate research performance focus on citation count, quality and quantity of research output by individual researchers. These measures overlook the roles an individual plays in research collaboration, which is critical in an institutional research management environment due to the inherent interdependency among research entities. In order to address the organizational research management needs, we propose a research social network approach to better analyze local collaboration networks. For this purpose, we develop a new “collaboration supportiveness” measure to quantify an individual researcher's collaboration ability. Insights derived from this research are very helpful for managers to effectively allocate resources, …

Filter-Based Multiscale Entropy Analysis Of Complex Physiological Time Series, Liang Zhao

Dissertations - ALL

The multiscale entropy (MSE) has been widely and successfully used in analyzing the complexity of physiologic time series. In this thesis, we re-interpret the averaging process in MSE as filtering a time series by a filter of a piecewise constant type. From this viewpoint, we introduce the {\it filter-based multiscale entropy} (FME) which filters a time series by filters to generate its multiple frequency components and then compute the {\it blockwise} entropy of the resulting components. By choosing filters adapted to the feature of a given time series, FME is able to better capture its multiscale information and to provide …

Precision Measurement Of The Lambda_B Baryon Lifetime, Bilas Kanti Pal

Dissertations - ALL

The ratio of the Lambda_b baryon lifetime to that of the B0 meson is measured using data corresponding to an integrated luminosity of 3.0 /fb collected with the LHCb detector using pp collisions at the LHC. The Lambda_b baryon is observed in the decay mode Lambda_b ->J/psi p K-, while the B0 meson decay used is the well known B0->J/psi pi+ K- mode, where the pi+K- mass is consistent with that of the K*0(892) meson. The ratio of lifetimes is measured to be 0.971+/-0.007+/-0.005, in agreement with theoretical expectations based on the heavy quark expansion. Using previous determinations …

The Solid State Simulation Of The Structure And Vibrational Modes Of Organic, Hybrid Organometallic And Inorganic Species Using The Crystal09 Code., Steven Pellizzeri

Dissertations - ALL

An investigation of the structural and vibrational information of organic, hybrid organometallic and inorganic species was conducted using solid-state density functional theory (DFT). In this work the solid state DFT modeling was accomplished using the CRYSTAL09 code to simulate the geometries and vibrational modes of a variety of systems. These studies included: (1) the investigation of three polymorphs of vanadium phosphate, (2) three studies involving the use of 5-(4-pyridyl)tetrazole, and lastly (3) the crystal structure and simulation of α,α,α’,α’-tetrabromo-p-xylene. The studies involving 5-(4-pyridyl)tetrazole are comprised of (a) the comparison of a new polymorph to previously published crystallographic information of the …

Iowa Waste Reduction Center Newsletter, December 2013, Iowa Waste Reduction Center Newsletter, December 2014

Iowa Waste Reduction Center Newsletter

Inside this Issue:

--- Another Year Has Come and Gone
--- Most Popular Reads of 2013
--- 2014 Recordkeeping Compliance Calendars Available
--- Reducing Wasted Food Workshop
--- Health Care - Food Waste Webinar
--- On-Site Review Revisit
--- Latest Blog Posts

Application Of Ntru Cryptographic Algorithm For Securing Scada Communication, Amritha Puliadi Premnath

UNLV Theses, Dissertations, Professional Papers, and Capstones

Supervisory Control and Data Acquisition (SCADA) system is a control system which is widely used in Critical Infrastructure System to monitor and control industrial processes autonomously. Most of the SCADA communication protocols are vulnerable to various types of cyber-related attacks. The currently used security standards for SCADA communication specify the use of asymmetric cryptographic algorithms like RSA or ECC for securing SCADA communications. There are certain performance issues with cryptographic solutions of these specifications when applied to SCADA system with real-time constraints and hardware limitations. To overcome this issue, in this thesis we propose the use of a faster and …

Comparison Of Mesh And Meshless Methods For Partial Differential Equations Of Galerkin Form, Wallace F. Atterberry

UNLV Theses, Dissertations, Professional Papers, and Capstones

There are two purposes of this research project. The first purpose is to compare two types of Galerkin methods: The finite element mesh method and moving least sqaures meshless Galerkin (EFG) method. The second purpose of this project is to determine if a hybrid between the mesh and meshless method is beneficial.

This manuscript will be divided into three main parts. The first part is chapter one which develops the finite element method. The second part (Chapter two) will be developing the meshless method. The last part will provide a method for combining the mesh and meshless methods for a …

Design And Fabrication Of An Infrared Optical Pyrometer Asic As A Diagnostic For Shock Physics Experiments, Jared Gordon

UNLV Theses, Dissertations, Professional Papers, and Capstones

Optical pyrometry is the sensing of thermal radiation emitted from an object using a photoconductive device to convert photons into electrons, and is an important diagnostic tool in shock physics experiments. Data obtained from an optical pyrometer can be used to generate a blackbody curve of the material prior to and after being shocked by a high speed projectile. The sensing element consists of an InGaAs photodiode array, biasing circuitry, and multiple transimpedance amplifiers to boost the weak photocurrent from the noisy dark current into a signal that can eventually be digitized. Once the circuit elements have been defined, more …

The Effects Of Self-Explanation And Reading Questions And Answers On Learning Computer Programming Language, Nancy Lee

UNLV Theses, Dissertations, Professional Papers, and Capstones

The current study explored the differential effects of two learning strategies, self-explanation and reading questions and answers, on students' test performance in the computer programming language JavaScript. Students' perceptions toward the two strategies as to their effectiveness in learning JavaScript was also explored by examining students' preferred strategy and the reasons for their choice. An online interactive tutorial instruction that implemented worked-examples and multimedia learning principles was developed for this study. A total of 147 high school students (ages ranging from 14 to 17) who were taking a Computer Introduction course participated in this study. The course was offered in …

The Detection Of A Light Echo From Sn 2007af, Dina Drozdov

All Theses

Type Ia supernovae are widely studied for their uniform properties, which make them ideal candidates for cosmological surveys. Although these exploding stars are popular targets, key funda-mental questions about their nature remain, and new techniques need to be developed to investigate the progenitor system and explosion mechanisms. Light echoes are created by light scattering off dust that reaches the observer after the direct path light from the explosion arrived and have been studied for the past 100 years. Light echoes from Type Ia supernovae are rare, with only a few cases being discovered in the past decades. Because light echoes …

Lithostratigraphic And Petrophysical Analysis Of The Middle Devonian Marcellus Shale At The Mamont Prospect, Westmoreland County, Pennsylvania, Ty Taylor

All Theses

The organic-rich Middle Devonian Marcellus Shale of the Appalachian basin is a rapidly developing natural gas play. Stratigraphic boundaries of the Marcellus Shale in Westmoreland County, Pennsylvania were identified using geophysical logs from 10 vertical gas-producing wells in a 23 sq. km area. Gamma-ray, bulk density, and resistivity well logs were examined to assess hydrocarbon potential. Values of porosity, total organic carbon (TOC), and water saturation (SW) were derived and mapped by incorporating well-log data into Marcellus-specific formulas. Gamma-ray, penetration (minutes per foot drilled), and mud-logging gas (total gas) from 12 horizontal wells from within the study area were also …

Sequential Autotrophic-Heterotrophic Culture Of Scenedesmus Spp. For Lipid Production, Jazmine Taylor

All Theses

Algae are fascinating organisms that are receiving growing attention for their versatility on many fronts of research areas. Immense amounts of research is being conducted to find solutions to challenges in energy and climate change. A large portion of research is focused on algae as a potential solution to both of these issues. The focus of this research is to look at algae closer to home as a local, economical resource to aid in solving both of these problems. The algal genus Scenedesmus was tested for growth in a bi-phased scheme: photoautotrophically for carbon sequestration then heterotrophically on glycerol for …

Aqueous Geochemistry Of Rhenium And Chromium In Saltstone: Implications For Understanding Technetium Mobility In Saltstone, Amanda Hatfield

All Theses

Incorporation of low level radioactive waste in cementitious materials is an important waste disposal technology in practice at a U.S. DOE facility, the Savannah River Site (SRS), Aiken, SC. One of the major risk drivers, technetium (99Tc)

Stimulated Raman Scattering In Micro Sphere Resonators, Ruoyu Zhang

All Theses

Micro sphere resonators that hold optical whisper gallery modes (WGMs) provide an innovative option for implementing micro optical resonators. The unique properties of the micro sphere resonator make it capable to introduce resonance for various optical phenomenon, like stimulated Raman scattering (SRS), in micron scale.

This thesis illustrates the characteristics of micro sphere resonators and demonstrates the resonance-enhanced SRS in micro sphere resonators with reduce threshold power. Both theoretical and experimental results are presented. Coupling model for WGM is derived in transfer matrix method. Simulation analyses for mode pattern of WGMs are solved based on mathematic model and finite element …

The Fabrication And Study Of Silver Nanoparticle Structures, Aubrie Pfirman

All Theses

Nanotechnology and the synthesis of nanoparticle systems are attractive in part because of interesting, tunable optical and electrical properties that are not observed with bulk material. Silver nanoparticles (Ag NPs) interact with visible light more efficiently than any other system due to the excitation of plasmon resonances, which are the collective oscillations of the free electron density. These collective oscillations produce an enhanced local electromagnetic (EM) field: this field is responsible for highly-utilized phenomena such as surface enhanced Raman scattering (SERS), enhanced fluorescence, surface enhanced infrared absorption (SEIRA), and many others. Many experiments have been conducted to optimize and tailor …

Assessing Growth Response To Climate Controls In A Great Basin Artemisia Tridentata Plant Community, Lorenzo F. Apodaca

UNLV Theses, Dissertations, Professional Papers, and Capstones

An assessment of the growth response of key vegetative species to climatic variability is vital to identifying possible local impacts on ecosystems faced with imminent climate change. With current climate projections in Nevada predicting a shift to an even more arid climate with greater year-to-year variability, the imperative exists to identify the effects of specific climatic controls on plant growth and to research methods to assess large-scale vegetative changes, especially in more remote areas where readily available data sets may be lacking. This study utilized annual growth ring indices constructed from big sagebrush (Artemisia tridentatassp.tridentata) stems collected in Spring Valley, …

Criticality And Characteristic Neutronic Analysis Of A Transient-State Shockwave In A Pulsed Spherical Gaseous Uranium-Hexafluoride Reactor, Jeremiah Boles

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study is to analyze the theoretical criticality of a spherical uranium-hexafluoride reactor with a transient, pulsed shockwave emanating from the center of the sphere in an outward-radial direction. This novel nuclear reactor design, based upon pulsed fission in a spherical enclosure is proposed for possible use in direct energy conversion, where the energy from fission products is captured through the use of electrostatic fields or through induction. An analysis of the dynamic behavior of the shockwave in this reactor is the subject of this thesis. As a shockwave travels through a fluid medium, the characteristics of …